The present invention relates to a radiation detector designed to be used, for example, in connection with x-ray tomography systems. The detector comprises a compact chamber with high pressure rare gas of high atomic weight. Cathodes and anodes, which are respectively connected to the negative and positive voltages of the direct current supply are located inside the chamber.
Similar ionization chambers are known which are utilized for detecting both the intensity and the location of x-rays. One example of a detector of this type is the apparatus presented in the U.S. Pat. No. 4,031,396. The said apparatus comprises an ionization chamber with gas of high atomic weight having a pressure of 10-50 atmospheres. Parallel planar anodes, separated by planar cathodes, are located inside the chamber. The planar anodes and cathodes are placed vertically towards the radiation direction. This apparatus measures the radiation intensity in analoguous form utilizing an electronic circuit, in other words, it measures the ionization current intensity. The drawback of an apparatus of this type is the comparatively slow movement of the positive ions in the chamber and the inaccuracy related the measurement of such extremely weak currents and their conversion into digital form. Crystal detectors, are also known in which the radiation intensity is expressed in analoguous form using a photomultiplier.